diff --git a/libraries/GCS_MAVLink/GCS.h b/libraries/GCS_MAVLink/GCS.h
index 1063962140..c0b1b658fb 100644
--- a/libraries/GCS_MAVLink/GCS.h
+++ b/libraries/GCS_MAVLink/GCS.h
@@ -401,6 +401,9 @@ protected:
     MAV_RESULT handle_command_battery_reset(const mavlink_command_long_t &packet);
     void handle_command_long(const mavlink_message_t &msg);
     MAV_RESULT handle_command_accelcal_vehicle_pos(const mavlink_command_long_t &packet);
+    MAV_RESULT handle_command_do_set_roi_sysid(const uint8_t sysid);
+    MAV_RESULT handle_command_do_set_roi_sysid(const mavlink_command_int_t &packet);
+    MAV_RESULT handle_command_do_set_roi_sysid(const mavlink_command_long_t &packet);
     virtual MAV_RESULT handle_command_mount(const mavlink_command_long_t &packet);
     MAV_RESULT handle_command_mag_cal(const mavlink_command_long_t &packet);
     virtual MAV_RESULT handle_command_long_packet(const mavlink_command_long_t &packet);
diff --git a/libraries/GCS_MAVLink/GCS_Common.cpp b/libraries/GCS_MAVLink/GCS_Common.cpp
index 5d7ae76feb..acb2f2f835 100644
--- a/libraries/GCS_MAVLink/GCS_Common.cpp
+++ b/libraries/GCS_MAVLink/GCS_Common.cpp
@@ -1294,6 +1294,9 @@ void GCS_MAVLINK::packetReceived(const mavlink_status_t &status,
         // the routing code has indicated we should not handle this packet locally
         return;
     }
+    if (msg.msgid == MAVLINK_MSG_ID_GLOBAL_POSITION_INT) {
+        handle_mount_message(msg);
+    }
     if (!accept_packet(status, msg)) {
         // e.g. enforce-sysid says we shouldn't look at this packet
         return;
@@ -3628,6 +3631,9 @@ MAV_RESULT GCS_MAVLINK::handle_command_long_packet(const mavlink_command_long_t
         break;
     }
 
+    case MAV_CMD_DO_SET_ROI_SYSID:
+        return handle_command_do_set_roi_sysid(packet);
+
     case MAV_CMD_DO_SET_ROI_LOCATION:
     case MAV_CMD_DO_SET_ROI:
         result = handle_command_do_set_roi(packet);
@@ -3835,6 +3841,27 @@ MAV_RESULT GCS_MAVLINK::handle_command_int_do_set_home(const mavlink_command_int
     return MAV_RESULT_ACCEPTED;
 }
 
+
+MAV_RESULT GCS_MAVLINK::handle_command_do_set_roi_sysid(const uint8_t sysid)
+{
+    AP_Mount *mount = AP::mount();
+    if (mount == nullptr) {
+        return MAV_RESULT_UNSUPPORTED;
+    }
+    mount->set_target_sysid(sysid);
+    return MAV_RESULT_ACCEPTED;
+}
+
+MAV_RESULT GCS_MAVLINK::handle_command_do_set_roi_sysid(const mavlink_command_int_t &packet)
+{
+    return handle_command_do_set_roi_sysid((uint8_t)packet.param1);
+}
+
+MAV_RESULT GCS_MAVLINK::handle_command_do_set_roi_sysid(const mavlink_command_long_t &packet)
+{
+    return handle_command_do_set_roi_sysid((uint8_t)packet.param1);
+}
+
 MAV_RESULT GCS_MAVLINK::handle_command_do_set_roi(const mavlink_command_int_t &packet)
 {
     // be aware that this method is called for both MAV_CMD_DO_SET_ROI
@@ -3887,6 +3914,8 @@ MAV_RESULT GCS_MAVLINK::handle_command_int_packet(const mavlink_command_int_t &p
     case MAV_CMD_DO_SET_ROI:
     case MAV_CMD_DO_SET_ROI_LOCATION:
         return handle_command_do_set_roi(packet);
+    case MAV_CMD_DO_SET_ROI_SYSID:
+        return handle_command_do_set_roi_sysid(packet);
     case MAV_CMD_DO_SET_HOME:
         return handle_command_int_do_set_home(packet);
     default: